Performing a midair fuel transfer between aircraft is among the most technically challenging maneuvers in aviation, especially when flying a prop-driven, WWII-era C-97 Stratotanker. That's why neophyte pilots spent hours at the controls of this life-size simulator before they ever set foot in the real thing.

Built in 1953 at a cost of $853,000—one of only eleven ever made—the KC-97 Stratotanker Simulator weighed a whopping nine tons and required a trio of technicians to operate. Its four analog computers had to be programmed before each training session via stacks of "resistance cards" that dictated the behavior of the simulator's 117 motor-driven resistors. According to a 1968 National Guard press release:

It is used to familiarize flight crews with proper pre-flight checks, starting and take-off procedures, normal and emergency flight operating procedures, fuel management, cruise control, landing procedures, radio communications procedures, and the use of navigational aids. It is crammed with a maze of dials, instruments, switches and other gear that surround the pilot, co-pilot and flight engineer.

This simulator appears to have remained in operation for a number of years as part of the 128th Air Refueling Wing of the Air National Guard, until at least the early 1970's when the 128th began upgrading its fleet to the newer KC-135S model. There's no word on what ever became of the simulator itself however. Hopefully it's still out there; we want to try one someday. [USAF via The Aviationist]